81546593 has 2 divisors, whose sum is σ = 81546594. Its totient is φ = 81546592.

The previous prime is 81546559. The next prime is 81546607. The reversal of 81546593 is 39564518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79423744 + 2122849 = 8912^2 + 1457^2 .

It is a cyclic number.

It is not a de Polignac number, because 81546593 - 2⁶ = 81546529 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81546593.

It is not a weakly prime, because it can be changed into another prime (81546503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40773296 + 40773297.

It is an arithmetic number, because the mean of its divisors is an integer number (40773297).

Almost surely, 2^81546593 is an apocalyptic number.

It is an amenable number.

81546593 is a deficient number, since it is larger than the sum of its proper divisors (1).

81546593 is an equidigital number, since it uses as much as digits as its factorization.

81546593 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129600, while the sum is 41.

The square root of 81546593 is about 9030.3152215191. The cubic root of 81546593 is about 433.6459290165.

The spelling of 81546593 in words is "eighty-one million, five hundred forty-six thousand, five hundred ninety-three".